(NewsTarget) Voting machines have caused controversy due to studies that say they are vulnerable to hacking and vote tampering, but Princeton University computer science professor Edward Felten and two graduate students, Ariel Feldman and Alex Halderman, have escalated these doubts by actually obtaining a commonly used electronic voting machine and hacking it.

Felten and his students acquired a Diebold AccuVote-TS from an undisclosed source and extensively tested the vulnerabilities of the machine. They found that by opening a locked panel in the back -- which one of the team picked in about 10 seconds -- and accessing the memory card slot and power button, they could alter votes made on the machine, crash it, and even piggyback malicious software to other networked voting machines. The team even developed software that would cover their tracks, hiding evidence of tampering from even comprehensive forensic study.

A spokesperson for the machine's manufacturer -- Diebold Inc.'s Diebold Election systems of Allen, Texas -- said Felten's report ignored new software and security measures that the company implements to prevent exactly the hacking the Princeton researchers simulated.

"I'm concerned by the fact we weren't contacted to educate these people on where our current technology stands," said Mark Radke, marketing director for Diebold.

Radke also questioned why Felten did not subject his paper to peer review before it was published on the university's web site, as is the standard for scientific research of this nature. Felten responded that he and his colleagues felt time was of the essence, due to the imminent midterm elections in November.

Estimates suggest about 80 percent of U.S. voters will use some form of electronic voting machine in the midterm elections, which will determine the makeup of the House, 33 Senate seats, and 36 governorships. The AccuVote TS is one of the most commonly used voting machines in the United States, along with its newer counterpart, the AccuVote-TSx. Felten admitted he was unable to obtain the TSx model for testing, but was sure much of the vulnerabilities he and his students uncovered would still apply.

"I think there are many people out there who have the type of technical ability to carry out the sort of attacks we describe here," Felten said.

Felten said the vulnerabilities he and his team found can be overcome with improved software and better protection for the memory card and power switch. He also suggested use of paper receipts that voters could verify.

According to Radke, Diebold has already put many of these strategies into practice.